Graphene preparation method

Abstract

The invention discloses a graphene preparation method, which comprises: adding 5 g of natural graphite powder to a mixed solution of sulfuric acid and nitric acid, uniformly stirring, and slowly adding 55 g of potassium chlorate; stirring the mixed solution for 96 h at a room temperature, repeatedly adding a 5% hydrochloric acid solution, carrying out centrifugation until no sulfate ion exists inthe solution, diluting with a large amount of deionized water, and carrying out centrifugation until the pH value of the filtrate is neutral; filtering the neutral solution with filtering paper havinga pore size of 0.5 [mu]m, baking for 24 h at a temperature of 80 DEG C, taking out, and grinding by an agate mortar to obtain graphite oxide powder; and placing the prepared graphite oxide in a tubular high-temperature furnace, vacuumizing for 5 min, introducing argon gas for 30 min to prevent the influence of external air on the process, heating to a temperature of 1100 DEG C at a heating rate of 60 DEG C/min, maintaining the temperature for 1 h, continuously introducing argon gas at a flow rate of 100 sccm during the heating, introducing hydrogen gas at a flow rate of 20 sccm to increase the reduction effect, and thermally stripping the oxidizable graphite to obtain graphene.

Description

technical field [0001] The invention relates to a preparation method of graphite material, in particular to a preparation method of graphene. Background technique [0002] As we know, with the massive exploitation and unlimited use of oil, the exhaust gas from automobiles causes severe air pollution, causing drastic changes in the climate around the world, which in turn triggers the greenhouse effect and causes holes in the ozone layer. Facing the challenges of air pollution and energy depletion Due to the double crisis, countries are actively looking for various solutions to save energy. [0003] Although phase change materials have the advantage of large latent heat value, the fatal shortcomings of low heat transfer rate and thermal melting deformation need to be solved. Many scholars at home and abroad try to use various fillers to improve the heat transfer efficiency and solidity of phase change materials. Scholars such as Mills and Sari add porous graphite and expanded...

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Problems solved by technology

[0003] Although phase change materials have the advantage of large latent heat value, the fatal shortcomings of low heat transfer rate and thermal melting deformation need to be solved. Many scholars at home and abroad try to use various fillers to improve the heat transfer efficiency and solidity of phase change materials. Scholars such as Mills and Sari add porous graphite and expanded graphite to the phase change material, but the carbon material needs to be added to 10wt.%. Above can improve the heat transfer capacity of the phase change material, but adding a large amount of carbon material will reverse The latent heat value and resistivity of the phase change material decrease. In addition, in order to solve the problem of deformation of the phase change material when it is heated and melted, some foreign scholars add high density polyethylene (HDPE) and other polymers to the phase change material as supporting materials. The heat transfer efficiency of phase change materials is even worse

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